To study the long-term effects of preschool programs for poor children, the High/Scope Educational Research Foundation has followed two groups of Michigan children since early childhood. One group of 62 attended preschool as 3- and 4-year-olds. A control group of 61 children from the same area and similar backgrounds did not attend preschool. Over a ten-year period as adults, 38 of the preschool sample and 49 of the control sample needed social services (mainly welfare). Solution b b c d a.